Mapas conceituais e o jogo: estratégias pedagógicas de ensino e aprendizagem de Bioquímica

O artigo relata e analisa a utilizaÁ„o de mapas conceituais aplicados ‡ avaliaÁ„o de conceitos aprendidos com o uso do jogo Diagrama MetabÛlico Din‚mico (DMD) na disciplina de BioquÌmica da FundaÁ„o Faculdade Federal de CiÍncias MÈdicas de Porto Alegre. Explora a validade do uso do mapa conceitual como ferramenta pedagÛgica, pelo estudante, na modelagem dos conceitos e autoavaliaÁ„ o; e pelo professor, no acompanhamento e avaliaÁ„o do processo de aquisiÁ„o de conhecimento pelo aluno. Cada participante, individualmente, construiu um mapa conceitual inicial, sobre um determinado metabÛlito indicado pelo professor. Em seguida, participou de uma atividade em grupo, montando, de forma colaborativa e cooperativa, um jogo sobre este metabÛlito e apÛs construiu, individualmente, novo mapa conceitual. Uma an·lise qualitativa comparativa foi feita entre os mapas conceituais inicial e final de cada participante. O inicial foi usado como indicador do conhecimento prÈvio do participante sobre o assunto trabalhado e o final para verificar a expans„o dos conceitos processados pelo aluno apÛs o jogo. Foram considerados os seguintes pontos: predomin‚ncia do car·ter associativo ou classificatÛrio; conceitos e relaÁ?es corretas; n?mero de relaÁ?es. Os mapas iniciais indicaram que todos os alunos possuÌam algum esquema mental prÈvio sobre o conceito proposto. Todos os mapas conceituais finais indicaram expans„o de conceitos em relaÁ„o aos mapas iniciais, o que pode ser percebido atÈ mesmo pela observaÁ„o do tamanho dos grafos. A observaÁ„o puramente visual comparativa entre os mapas mostra que houve uma agregaÁ„o de novos elementos. Evidenciou-se a predomin‚ncia do car·ter associativo em relaÁ„o ao car·ter classificatÛrio. Os resultados apresentados sugerem a validade do uso do mapa conceitual como estratÈgia de acompanhamento do processo cognitivo, pelo professor e pelo prÛprio aluno

Short-term pacing in the mouse alters cardiac expression of connexin43

Background: Cardiac insults such as ischemia, infarction, hypertrophy and dilatation are often accompanied by altered abundance and/or localization of the connexin43 gap junction protein, which may predispose towards arrhythmic complications. Models of chronic dyssynchronous cardiac activation have also been shown to result in redistribution of connexin43 in cardiomyocytes. We hypothesized that alterations in connexin43 expression and localization in the mouse heart might be induced by ventricular pacing over a short period of time. Results: The subdiaphragmatic approach was used to pace a series of wild type mice for six hours before the hearts were removed for analysis. Mice were paced at 10–15% above their average anesthetized sinus rate and monitored to ensure 1:1 capture. Short-term pacing resulted in a significant reduction in connexin43 mRNA abundance, a partial redistribution of connexin43 from the sarcolemma to a non-sarcolemmal fraction, and accumulation of ubiquitinated connexin43 without a significant change in overall connexin43 protein levels. These early pacing-induced changes in connexin43 expression were not accompanied by decreased cardiac function, prolonged refractoriness or increased inducibility into sustained arrhythmias. Conclusion: Our data suggest that short-term pacing is associated with incipient changes in the expression of the connexin43 gap junction, possibly including decreased production and a slowed rate of degradation. This murine model may facilitate the study of early molecular changes induced by pacing and may ultimately assist in the development of strategies to prevent gap junction remodeling and the associated arrhythmic complications of cardiac disease

Cortical thickness and resting-state cardiac function across the lifespan: a cross-sectional pooled mega analysis

Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS – or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between cortical thickness and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research

Conceptual maps and a game: pedagogic strategies for biochemistry teaching and learning

O artigo relata e analisa a utilização de mapas conceituais aplicados à avaliação de conceitos aprendidos com o uso do jogo Diagrama Metabólico Dinâmico (DMD) na disciplina de Bioquímica da Fundação Faculdade Federal de Clínicas Médicas de Porto Alegre. Explora a validade do uso do mapa conceitual como ferramenta pedagógica, pelo estudante, na modelagem dos conceitos e auto-avaliarão ; e pelo professor, no acompanhamento e avaliação do processo de aquisição de conhecimento pelo aluno. Cada participante, individualmente, construiu um mapa conceitual inicial, sobre um determinado metabólito indicado pelo professor. Em seguida, participou de uma atividade em grupo, montando, de forma colaborativa e cooperativa, um jogo sobre este metabólito e após construiu, individualmente, novo mapa conceitual. Uma análise qualitativa comparativa foi feita entre os mapas conceituais inicial e final de cada participante. O inicial foi usado como indicador do conhecimento prévio do participante sobre o assunto trabalhado e o final para verificar a expansão dos conceitos processados pelo aluno após o jogo. Foram considerados os seguintes pontos: predominância do caráter associativo ou classificatório; conceitos e relações corretas; número de relações. Os mapas iniciais indicaram que todos os alunos possuíam algum esquema mental prévio sobre o conceito proposto. Todos os mapas conceituais finais indicaram expansão de conceitos em relação aos mapas iniciais, o que pode ser percebido até mesmo pela observação do tamanho dos grafos. A observação puramente visual comparativa entre os mapas mostra que houve uma agregação de novos elementos. Evidenciou-se a predominância do caráter associativo em relação ao caráter classificatório. Os resultados apresentados sugerem a validade do uso do mapa conceitual como estratégia de acompanhamento do processo cognitivo, pelo professor e pelo próprio aluno.This paper reports on the use of concept maps applied to the evaluation of concepts learned through the use of the game Dynamic Metabolic Diagram (DMD - described in Biochemical Education, vol. 20, n 2, p. 97-98, 1992) in the discipline of Biochemistry of FFFCMPA. An investigation was carried out into the validity of using concept maps as a pedagogical tool both by the student, in the modeling of concepts, and by the teacher, in the assessment of the studentís learning. Each participant constructed an initial concept map about a given metabolite assigned by the teacher. Subsequently, he or she participated in a group activity, playing an educational game about this metabolite, and later the student constructed a new concept map. A comparative qualitative analysis was carried out between the initial and final concept maps of each participant The initial concept was used as an indicator of the participantís previous knowledge of the topic, and the final concept was used to check the expansion of the concepts by the student after playing the game. The following criteria were used: predominance of associative or classificatory character; correct concepts and relationships; number of relationships. A purely visual comparison between the maps indicated that new elements have been added. The associative character has been shown to predominate when compared to the classificatory one. The results obtained suggest the validity of using concept maps as a strategy to monitor the cognitive process, both by the teacher and by the student

Decreased connexin43 expression in the mouse heart potentiates pacing-induced remodeling of repolarizing currents

Gap junction redistribution and reduced expression, a phenomenon termed gap junction remodeling (GJR), is often seen in diseased hearts and may predispose toward arrhythmias. We have recently shown that short-term pacing in the mouse is associated with changes in connexin43 (Cx43) expression and localization but not with increased inducibility into sustained arrhythmias. We hypothesized that short-term pacing, if imposed on murine hearts with decreased Cx43 abundance, could serve as a model for evaluating the electrophysiological effects of GJR. We paced wild-type (normal Cx43 abundance) and heterozygous Cx43 knockout (Cx43+/−; 66% mean reduction in Cx43) mice for 6 h at 10–15% above their average sinus rate. We investigated the electrophysiological effects of pacing on the whole animal using programmed electrical stimulation and in isolated ventricular myocytes with patch-clamp studies. Cx43+/− myocytes had significantly shorter action potential durations (APD) and increased steady-state (Iss) and inward rectifier (IK1) potassium currents compared with those of wild-type littermate cells. In Cx43+/− hearts, pacing resulted in a significant prolongation of ventricular effective refractory period and APD and significant diminution of Iss compared with unpaced Cx43+/− hearts. However, these changes were not seen in paced wild-type mice. These data suggest that Cx43 abundance plays a critical role in regulating currents involved in myocardial repolarization and their response to pacing. Our study may aid in understanding how dyssynchronous activation of diseased, Cx43-deficient myocardial tissue can lead to electrophysiological changes, which may contribute to the worsened prognosis often associated with pacing in the failing heart

Short-term pacing in the mouse alters cardiac expression of connexin43-0

Er the pacing experiment to demonstrate that the tip of the stimulating electrode is positioned at the epicardial surface of the right ventricle. M-mode echocardiography reveals dyssynchrony of ventricular contraction during subdiaphragmatic pacing with a substantially greater delay in the time between septal (yellow arrow) and posterior wall thickening (red arrow) compared to non-paced baseline. Septal-to-Posterior Wall Motion Delay (SPWMD), a measurement of the time interval between septal and posterior wall systolic thickening as demonstrated in Panel A, is significantly prolonged during pacing in comparison to the SPWMD measured prior to initiation of pacing. A surface electrocardiogram recorded during pacing demonstrates a wide and aberrantly conducted paced complex in comparison to a sinus beat recorded before pacing.<p><b>Copyright information:</b></p><p>Taken from "Short-term pacing in the mouse alters cardiac expression of connexin43"</p><p>http://www.biomedcentral.com/1472-6793/8/8</p><p>BMC Physiology 2008;8():8-8.</p><p>Published online 6 May 2008</p><p>PMCID:PMC2396665.</p><p></p